Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the mealybug Pseudococcus obscurus Essig (Pseudococcidae) two esterases, a tyrosinase and a mannosephosphate isomerase, exhibited an unusual type of maternal inheritance. Electromorphs (alleles) were transmitted by both parent but segregation was delayed by one generation and full sisters always had the same phenotype. Moreover, for esterase-1, in which three alleles were present, some of the females exhibited all three alleles. Several other polymorphic loci exhibited normal transmission and segregation. This mode of inheritance can be readily explained by assuming that most or all of the enzymes coded for by these loci are produced by the mycetocytes. The mycetocytes house intracellular bacteria-like symbionts and are usually formed by the fusion ofthe polar bodies and one or more cleavage nuclei. For a locus with two alleles exhibiting this type of inheritance, the expected frequencies of the three phenotypes are p3, 3pq an equation is presented for estimating the frequency of alleles from the frequencies of the phenotypes and it is shown that for three samples from wild populations there is a good agreement between the expected and observed frequencies of the phenotypes.
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PMID:Maternal inheritance of enzymes in the mealybug Pseudococcus obscurus (Homoptera). 40 24

The histochemistry of armadillo skin has been studied. The dendritic cells are extremely large, very sharply outlined by methods for alkaline phosphatase and alpha-naphthyl-acetate esterase, and they are dopa-negative. The mastocytes, however, are dopa-oxidase-positive, probably due to peroxidase rather than tyrosinase activity. The giant cells of the granulomas normally seen in the dermis of the armadillo are strongly beta-glucuronidase-positive. These giant cells are evidently foreign body cells reacting to the crystals always present in the dermis of the armadillo. The centre of these crystals, which are cholesterol and fat-negative, is alkaline phosphatase-positive. Further study of the mastocytes and dendritic cells is necessary to elucidate their nature.
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PMID:The histochemistry of armadillo skin. 81 35

The dermal cells in grey, xanthic, and white goldfish integuments were cytochemically characterized for the following enzymatic activities: tyrosinase, DOPA-oxidase, cytochrome oxidase, monoamine oxidase, peroxidase, non-specific esterase, cholinesterase, NAD-diaphorase, NADP-diaphorase, aryl sulfatase, nucleotide phosphodiesterase, beta-glucuronidase, acid phosphatase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, glucose-6-phosphatase, aldolase, as well as succinate, malate, isocitrate, glutamate, glucose-6-phosphate, 6-phosphogluconate, alpha-glycerophosphate, alcohol, lactate, and beta-hydroxybutyrate dehydrogenases. It was found that the epidermis was a significant barrier to the access of cytochemical reaction substrates. Removal of the epidermal barrier provided dermal cell localizations of enzymatic activities which were reproducible. Further, alterations in reaction times and temperatures from the mammalian methodology provided conditions fe various integumental cells were compared for possible interrelationships. The basic foundations for future work with the dermis of poikilothermic vertebrates on an experimental basis were established. In addition, a previously undescribed non-pigmented dermal cell, the "x"-cell, was found to have enzymatic characteristics similar to both melanophores and lipophores. The "x"-cell may be the common precursor of both types of pigment cells.
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PMID:Cytochemical characterization of goldfish (Carassius auratus L.) dermis with special reference to the pigment cells. 82 86

Substituted phenolic compounds were previously shown to exhibit cytotoxicity towards epithelial cells in the presence of the enzyme tyrosinase as a result of the formation of their quinone products. Seventeen of these compounds were tested for cytotoxic properties towards three different melanoma cell lines. The compounds were split into four groups of phenol derivatives, A; alkoxyethers, including 4-hydroxyanisole (4HA), B; oxyethers derivatized at the acyl side chain, C; oxyethers derivatized at the phenol, and D; acyl thioethers. Toxicity was determined by total cell counts after 3 days exposure to the compounds. Large reductions in cell numbers were observed with 4HA (the methoxy-), ethoxy-, propoxy and iso-butoxyethers of group A and the methyl- and propyl thioethers of phenol of group D. Derivatization of the ethoxy- and propoxy side chains (group B) did not seem to increase the cytotoxic effects, as determined by cell counts. Compounds of group C, which need intracellular esterase activity to release the phenols, showed moderate toxicities. Toxicity of certain compounds was confirmed by LDH release into the culture medium and by increased trypan blue uptake of cells exposed to the compounds. Flow cytometric investigations of cells after exposure for 24 h revealed that most compounds caused an increase in the proportion of cells in G1 phase. A complete accumulation of cells in S-phase was observed after exposure to 4-ethoxyphenol. Inhibition of DNA synthesis was also shown by inhibition of bromodeoxyuridine incorporation. The results presented show that phenolic compounds exhibit cytotoxic properties towards melanoma cells some of which may be mediated by tyrosinase activity. Toxicity of the compounds was shown to be exerted during DNA replication but their toxic action may also be due to membrane damage and inhibition of cell metabolism.
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PMID:Cytotoxicity of a selected series of substituted phenols towards cultured melanoma cells. 129 81

Analysis of restriction fragment length polymorphism (RFLP) is a powerful tool for analyzing linkage relationships in species where few genetic markers have been described and where conduct of crosses is difficult. It also permits integration of genetic and physical (cytogenetic) data when the probes have been mapped by in situ hybridization. To illustrate the utility of the method, and because some mutations of a diphenol oxidase gene might conceivably produce the malaria refractoriness phenotype of ookinete-oocyst encapsulation, backcrosses between two inbred lines of Anopheles gambiae Giles were carried out to determine the linkage relationship between the diphenol oxidase A2 (Dox) gene and the esterase locus associated with refractoriness to Plasmodium cynomolgi NIH. The Dox alleles were a Sal I restriction fragment length polymorphism visualized by probing Southern blotted DNA from portions of individual mosquitoes with a cloned Dox gene probe. The two genes were shown to segregate independently.
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PMID:Use of a restriction fragment length polymorphism (RFLP) as a genetic marker in crosses of Anopheles gambiae (Diptera: Culicidae): independent assortment of a diphenol oxidase RFLP and an esterase locus. 167 45

The ability to degrade oligo- and polysaccharides by enzymes of the glycosidase and glucan-glucan hydrolyse type, and esterase, phosphatase, proteinase, peroxidase, catalase, laccase and tyrosinase activities were tested in 35 strains of 11 sections of the genus Fusarium.
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PMID:Enzyme apparatus of the genus Fusarium. 624 4

The oxidative end products that result from the biocatalysis of tyrosinase (PPO) and/or a polyphenol esterase (PPE) extract have been investigated simultaneously in model systems containing selected phenolic compounds as substrates. The spectrophotometric scanning of brown color, formed in the presence of both PPO and PPE, showed a decrease in the absorbance compared to that obtained with PPO only. Graphical analyses of the iterative spectra of oxidized phenolic end products by PPO confirmed the presence of, at least, three kinetically related absorbing species. HPLC analyses of the end products, obtained by the biocatalysis of PPE or PPO activity, indicated the presence of two main groups of compounds: colored ones of lambda(max) at 294-324 nm and colorless products of lambda(max) at 264-290 nm. PPE produced both compounds when selected substrates were used as substrates, whereas PPO produced only one type of oxidation product. However, when both enzymes were incubated together, the nature of the end products was similar to that obtained with PPE only.
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PMID:Characterization of tyrosinase- and polyphenol esterase-catalyzed end products using selected phenolic substrates. 1079 54

Molecular characterisation of clonal apple rootstocks using isozymes was carried out to identify isozyme polymorphism in seven clonal apple rootstocks and to identify the most characteristic and stable enzyme markers for each individual rootstock. Five enzyme systems were studied out of which polyphenol oxidase, malate dehydrogenase, acid phosphatase and peroxidase were useful in discriminating among the rootstocks. The peroxidase enzyme system showed maximum variation and esterase showed the least variation among the rootstocks. Out of seven rootstocks, three were distinguished on the basis of one enzyme system only (M.3 with MDH or PER, M.7 with PPO or PER and MM. 111 with MDH). Out of the sixteen loci studied seven were found to be polymorphic. Genetic variation among the rootstocks was explained on the basis of various parameters. The percentage of polymorphic loci varied from 13.33 to 35.71 per cent.
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PMID:Distinguishing clonal apple rootstocks by isozymes banding patterns. 1190 9

Amphibia Kupffer cells (i.e., liver resident macrophages) show many common characteristics when compared with Mammalia Kupffer cells: filopodia, microvillous-like structures, lamellipodia, fuzzy coat, coated vesicles, bristled vacuoles, nonspecific esterase activity, and pinocytotic and phagocytic activity are present both in Amphibia and Mammalia Kupffer cells. On the other hand, some differences are present between Kupffer cells of both zoological classes: phagocytosed red cells and their derivatives, iron-protein complexes, and lipofuscin bodies are normally present in Amphibia Kupffer cells, but absent in the same cells of healthy mammals. Worm-like structures are not seen in Amphibia and endogenous peroxidase activity is very weak in these animals compared with Mammalia. The most important difference lies in the ability of Amphibia Kupffer cells to produce melanins: in fact the tyrosinase gene is expressed, "melanosome centers" are present, and dopa oxidase activity is demonstrable.
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PMID:Amphibia Kupffer cells. 1211 30

By means of polyacrylaminde gel eletrothoresis and thin layer scanning, the paper semi-quantitatively studies some relation between component and activity of isoenayme of Ginseng infecting red skin desease. The results show activity of esterase increases 100% than that of normal Ginseng; activity of polyphenol oxidase increases 60-30% and represent new isoenzyme bands in the early infection in juxtapose transolant experiment.
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PMID:[Enzynology of infected part of red skin ginseng]. 1257 69


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